diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
index 4def1b7266f6..e331b57d6d7d 100644
--- a/drivers/tty/serial/sc16is7xx.c
+++ b/drivers/tty/serial/sc16is7xx.c
@@ -678,6 +678,8 @@ static void sc16is7xx_handle_tx(struct uart_port *port)
 
 	if (uart_circ_empty(xmit))
 		sc16is7xx_stop_tx(port);
+	else
+		sc16is7xx_ier_set(port, SC16IS7XX_IER_THRI_BIT);
 	uart_port_unlock_irqrestore(port, flags);
 }
 
@@ -804,7 +806,6 @@ static void sc16is7xx_tx_proc(struct kthread_work *ws)
 {
 	struct uart_port *port = &(to_sc16is7xx_one(ws, tx_work)->port);
 	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
-	unsigned long flags;
 
 	if ((port->rs485.flags & SER_RS485_ENABLED) &&
 	    (port->rs485.delay_rts_before_send > 0))
@@ -813,10 +814,6 @@ static void sc16is7xx_tx_proc(struct kthread_work *ws)
 	mutex_lock(&one->efr_lock);
 	sc16is7xx_handle_tx(port);
 	mutex_unlock(&one->efr_lock);
-
-	uart_port_lock_irqsave(port, &flags);
-	sc16is7xx_ier_set(port, SC16IS7XX_IER_THRI_BIT);
-	uart_port_unlock_irqrestore(port, flags);
 }
 
 static void sc16is7xx_reconf_rs485(struct uart_port *port)